Electronic counting device



June 4 I' J. s. COMPTON ET AL I 3 5 ELECTRONIC COUNTING DEVICE FiledMay' 6, 1943 X X X X X X X X X X X X Juan s. Compton and Robert E MummaInventors Their Attornev x H SQ m G RM H Wm w H Nm C m 2 l N\\ Q F- QR58 Q S m an. 5 4 LI 4 RJ O 6% QE QKE EK Patented June 18, 1946 OFFICEELECTRONIC COUNTING DEVICE Justin S. Compton, Lebanon, and Robert E.Mumma, Dayton, Ohio, assignors to The National Cash Register Company,Dayton, Ohio, a corporation of Maryland Application May 6, 1943, SerialNo. 485,850 Claims. (01. 315-323) This invention relates to anelectronic counting device wherein four counting tubes may be used tocount up to ten.

The electron tubes are of the gaseous type and are connected in acircuit so that, upon receipt of electric impulses commonly impressed onthe tubes, they will be actuated diiTerenti-ally serially andcyclically, so that the accumulated count is determined by the positionof the tube or tubes thatare in a conducting state. Upon the receipt ofthe tenth count, the tubes are automatically reset to azero-representing state, wherein the tubes are non-conducting.

It is the principal object of the invention to provide a decimalelectronic counting device based on a four-place combination code.

Another object of the invention is to provide means to differentiallyactuate a group of electron tubes by impulses which cause said tubes tobe discharged in a diminishing cyclic operating pattern, step by step,wherein one or more tubes may be in a conducting condition at a giveninstant.

Another object of the invention is to provide novel unidirectionalextinguishing means for operating a chain-connected group of electrontubes serially. I

With these and incidental objects in view, the invention includescertain novel features of circuits and circuit elements, the essentialsof which are hereinafter set forth in appended claims and a preferredform or embodiment of which is hereinafter described with reference tothe drawing which accompanies and forms a part of this specification.

In the drawing:

2 resistance I8. The .point [9 is connected to the grid or said tube Inthrough a resistor 20 of 500,000 ohms, point 2|, and resistor 22 of50,000 ohms.

'Ihegrids of tubes ll, l2, and I3 are given a normal negative bias ofabout 65 volts withrespect to ground by being connected to, conductor llthrough a resistor of 150,000 ohms, like resistor 23, and connected toground through a 100,000- ohm resistor, like resistor 24, in series withthe 15,000-ohm cathode resistor 25. Resistors like resistors 26 and 21have the same value for all the tubes H], H, l2, and I3. The grid ofeach of the tubes lll,'ll, I 2, and I3 is connected to input impulseconductor 30 through an individual capacitor like capacitor 3| of l0micro-microfarads to a point corresponding to point 2! Between thecathodes of tubes 10 and H is a capacitor 40 of approximately .005micro'farad in.

series with a rectifier oriented to pass positive impulses from thecathode of tube ll to the cathode of tube [0. Similar chain connectionsare made between the cathodes of tubes II and i2, and between thecathodes of tubes l2 and I3, .positive impulses produced anywhere onsaid chain passing toward the beginning of the chain as represented bythe cathode of .tube In.

On application of a positive potential impulse of approximately 2'5volts on conductor 30, assuming that no tube is conducting, the tube IIwill become conducting, as its grid is near enough the critical point tolose control on receipt of such Fig. 1 is a diagram of th circuit andelements I of the counting device. a Fig. 2 is a representation of thefour-place code used in representing the decimal system wherein the X"represent conducting tubes.

General description impulse. Tubes of the type mentioned fire when theassociated grid is at any potential more positive than about 12 voltsnegative with respect to the cathode potential. This is condition 1shown in Fig. 2, wherein the I tube I0 is conducting, it being assumedthat all of tube III, II, l2, and I3 are non-conducting at the beginningof an operation. However, as tube Ill becomes conducting, its cathoderises in potential almost volts, to within 15 volts of the anodepotential, which changes the potential of the grid of tube ll, as-thecathode of tube lfl is connected to grid biasing point 50, to about 25volts negative with respect to the cathode of the II tube ll.

On the next positive im ulse received on conductor 30, the II tube IIwill therefore become conducting, and a positive impulse caused by therise in its cathode potential will be conveyed through rectifier M andcapacitor 40 to the cath ode of the I tube In, causing it to overshootthe anode potential, thus extinguishing tube 40, vThis is condition 2shown in Fig. 2, wherein only 3 the II tube N (Fig. 1) is leftconducting. On receipt or the next impulse, tubes In and l2- will becomeconducting (as tube In is always ready, to conduct on receipt of animpulse if not then conducting and the III tube I2 is primed to becomeconducting by reason of the II tube having been conducting). .As the IIItube I2 becomes conducting, the impulse caused by the rise in potentialof its cathode is conveyed through the rectifiers 60 and to extinguishtubes l and II. This is condition 3'? shown in Fig. 2. On receipt of thefourth impulse, tubes |0.and l3 become conducting, and tubes I0 and |2are extlnguished as the positive rise in potential of the cathode oftube I3 is transmitted through rectifiers 99, 60, and 4| and theirassociated capacitors. On receipt of the fifth impulse, tube l0 becomesconducting and stays conducting, and tube the first time, is in effect;'I'his.first part of condition"0" is in effect for an instant only, asthereafter all the tubes are extinguished by the action of tubes 10 andH sending an extinguishing impulse through rectifier H3 and capacitorH2, as.

' will next be described.

Vacuum type electron tubes 10 and H (which ing, Point 9| will be 20volts negative; with three tubes, of tubes III, 12, and i3, conducting,point 9| will be 10 volts negative; and with the four tubes l0, ll, l2,and J3 conducting (which is the 0 condition), point 9| will be at groundpotential and tube II will commenceto conduct.

As soon as tube 1| commences to conduct, its

anode drops in potential to about 15 volts positive due to the eflect ofresistor 89, which transmits a sharp negative impulse through points 83and 81, through resistor 96 in parallel with capacitor H0, or -.005microfarad; and points 85 and 82 to the control grid of tube 10;stopping conduction therein, which causes a sharp positive potentialimpulse at point I, which positive impulse is transmitted, throughcapacitor 2 of .005 microfarad and rectifier H3, to the cathodes of allthe tubes I, ll, I2, and I3, extinguishing them.

The internal capacity of the rectifiers H3, 99, 80, and 4| must be keptas small as necessary to convey the extinguishing impulsesunidirectionally. If desired, diode vacuum electron tubes may be used asrectifiers, but low-capacity rectifiers of other types will do.

As soonas all the tubes are extinguished, which condition is shownontthe bottom line of conmay be of the 6AG7 type) each have theiroath-4" odes grounded and have their anodes connected to the 75-voltpositive supply conductor l4, each through a resistor like resistors 80and.89 of 3,000 ohms each. Each vacuum tube has a screen grid connectedto the '75-volt positive conductor l4 through point 8|. Each vacuum tubehas a suppressor grid connected to its cathode. Tubes 10 and H each havea control grid; The control grid of tube 10 is connected through point82, resistor 84 of 150,000 ohms, and point 83 to the 150-volt negativesupply conductor l1, and is connected through point 82, point 85,resistor 06 of 50,000 ohms, point 81, point 88, and resistor 89 of 3,000ohms to the positive 75-volt supply conductor l4, which gives the saidcontrol grid of tube 10 a normal potential of about 20 volts, positivewith respect to the cathode, which causes said tube to be normallyconducting.

The vacuum tube H is normally non-conductm as its control grid isconnected through point 90 and point 9| to conductor 92, which isconnected through resistor 93 of 250,000 ohms to 25,000-ohmpotentiometer 94, which grounds the negative 150-v0lt conductorConductor 92 is connected to the cathode of the I tube l0 through the500,000-ohm resistor 95; is connected to the cathode of the II tube l Ithrough 500,000-ohm resistor 96 and rectifier 4|; i connected to thecathode of III tube l2 through 500,000-ohm re-. slstor 91 and rectifier60; and is connected to the cathode of the IV tube l3 through500,000-ohm resistor 98 and rectifier 99. Under these circumstances,when no tube of tube |-0, l2, and I3 is conducting, the potentiometer isadjusted so that point 9| and the control grid of tube H are at 40 voltsnegative potential with respect to ground, and hence tube 1| is normallynon-conducting. As one tube of the four I 0, II, l2, and l 3 isconducting, point 9| becomes less negative to 30 volts negative withrespect to ground; with dition 0 (Fig. 2), tube II will again have acontrolling bias on its control, grid, stopping conduction therein. Tube10 will therefore begin to conduct. Thecapacity connection of .005microfarad of the control grid of tube 1| with the anode of tube 10 isprovided to produce a rapid change in the mode of operation of tubes 10and 1|, which act as a modified trigger pair.

The circuit values have-been given for illustration only, in connectionwith the characteristics of certain tubes mentioned, and they are notdeemed to limit the principle of the invention."

It is to be observed, that in counting to ten, the tubes are operatedserially in four cycles, each of which cycles has one less tube changingits operating condition. In the first cycle, tubes I, II, III, and IVare fired. In the second cycle,

tubes I, II, and III are fired. In the third cycle,

tubes I and III are fired. In the fourth cycle, tube I is fired alone.

The potential rise at point I I as tube 10 ceases conducting may be used.to cause a positive input impulse upon the input conductor to anotherhigher denominational counting device, like the one shown in Fig. 1, toactuate it one step for each ten impulses introduced into the lowerdenomination. Thus a multiple denominational counting device isprovided. The next higher de- I nomination counting device need notnecessarily be of the type herein described if it is responsive to sucha denominational carry over electric im- Pulse.

Capacitor I25 of 4 microfarads is introduced for filtering purposes Itwill be obvious to those skilled in the art that the extinguishingcircuits including the rectifiers and capacitors may be used to connectobjects primarily stated, it is t be understood that it i not intendedto confine the invention to the one form or embodiment herein disclosed,for it is susceptible of embodiment in various forms all coming withinthe scope oi the claims which follow.

What is claimed is: 1

1. In combination, a plurality of gaseous discharge electron tubes eachhaving at least an anode, a cathode, and a control grid; means supplyinganode-cathode potential to each tube sufchain non-conducting wherebyupon receipt of a number of impulses equal to ficient to maintainconduction therein, said means including a resistance in each cathodesupply; means for'supplying normal potential to the grids more negativethan the critical point of said tubes, the potential supplied to one ofthe grids being nearer the critical point than that of the other grids;means to impres positive electric impulses commonly on all of the gridssufllcient to cause conduction in said one tube whose grid is nearestthe critical point; means connecting the tubes in a chain cathode togrid, the first of the tubes in the chain being the one with itspotential nearest the critical point, the cathode rise of a conductingtube causing the next tube in the chain to beresponsive to the nextreceived impulse by becoming conducting; and means coni where N equalsthe number of tubes, all of the tubes will be conducting; and meansoperative when all the tubes are conducting to cause all of them tobecome non-conducting. t

*4. A-plurality of gaseous discharge electron tubes; means supplyingthem with operating potential; means normally preventing conduction inany tube; means to impart electric impulses tothe preventing means ofall the tubes which tend to render the preventing means ineffective toall the tubes and the first or any subsequent impulse of which causes afirst one of such tubes to conduct; chain connections between the tubeswhereby the condition of conduction of a tube renders the next tube inthe chain to such conducting tube conducting on receipt of the nextimpulse; extinguishing connections between the tubes whereby the act ofconduction commencing in any tube immediately thereafter renders allplreceding tubes of the chain non-conducting whereby upon receipt of anumber of impulses in any tube; means to impart electric impulses to thepreventing means of all the tubes'which impulses tend to render thepreventing means ineffective to all the tubes and the first or anysubsequent impulse of which means causes a first one of such tubes toconduct if not then conducting; chain connections between the tubeswhereby the condition of conduction of a tube renders the next tube inthe chain to such conducting tube conducting on receipt of the nextimpulse; and extinguishing connections between the tubes whereby the actof conduction commencing in any tube immediately thereafter renders allpreceding tubes of the chain non-conducting whereby upon receipt of anumber oi impulses equal to where N equals the number of tubes, all ofthe tubes will be conducting;

3. A plurality of gaseous discharge electron tubes; means supplying themwith operating potential; means normally preventing conduction in anytube; means to impart electric impulses to the preventing means of allthe tubes which tend to render the preventing means ineffective to allthe tubes and the first or any subsequent impulse of which causes afirst one of-such tubes to conduct if not then conducting; chainconnections between the tubes whereby the condition of conduction of atube renders the next tube in the equal to where N equals the number oftubes, all of the tubes will be conducting; and an electron tubehaving'an anode, a cathode, and a control grid arranged in the potentialsupply means so as to be conducting always except when all the chainconnected tubes are conducting.

5. A plurality .of gaseous discharge electron tubes; means supplyingthem with operating potentialj means normally preventing conduction inany tube; means to impart electric impulses to the preventing means ofall'the tubes which tends to render the preventing meansinefiective toall the tubes and the first or any'supsequent impulse of which causes afirst one of such tubes to conduct; chain connections between the tubeswhereby the condition of conduction of a tuberenders the next tube inthe chain to such conducting tube conducting on receipt of the nextimpulse; extinguishing connections between the tubes whereby the act ofconduction commencing in a tube immediately thereafter renders allpreceding tubes of the chain non-conducting whereby upon receipt of anumber of impulses equal to 7 where N equals the number of tubes, all ofthe chain to such conducting tube conducting on receipt of the nextimpulse; extinguishing connections between the tubes whereby the act ofconduction commencing in any tube immediately thereafter renders allpreceding tubes of the tubes will be conducting; a vacuum electroncontrol tube having an anode, a cathode, and a control grid arranged inthe potential supply means so as to be normally conducting except whenall the chain connected tubes are conducting and having a resistance inits anode supply circuit; and means connecting the anode to theextinguishing connections so that the positive rise in potential of theanode as the control tube becomes non-conducting will cause all of thechain connected tubes to become non-conducting.

6. A plurality of gaseous discharge electron tubes; means supplying themwith operating potential; means normally preventing conduction in anytube; mean to impart electric impulses to the preventing means of allthetubes which 4 non-conducting whereby upon receipt of a number ofimpulses equal to where N equals the number of tubes, all of the tubeswill be conducting; a vacum electron control tube having an anode, acathode, and a control grid arranged in a potential supply circuit so asto be normally conducting except when all the chain connected tubes areconducting and having a resistance in'its anode supplycircuit; and meansconnecting the anode to the extinguishing connections so that thepositive rise in potential of the anode as the control tube becomesnon-conducting. will cause all of the chain connected tubes to becomenon-conducting,- said control tube again becoming conducting as all thechain connectedtubes become non-conducting.

7. A plurality of gaseous discharge triode electron tubes; electricsupply means for said tubes suflicient to maintain conduction in anytube, the supply means for a tube including resistance; electricbiassupply means for normally preventing a discharge in any of saidtubes; electric impulse input meansscommon to said tubes tending torender said tubes conducting but normally insuii'icientto do so to anybut a first tube of the plurality; means interconnecting the tubes intoan operative chain whereby the condition of conduction in a tube primesthe next tube of the chain to become conducting on receipt of the nextimpulse despite the bias; and connections between the tubes operative byreason of said resistance for extinguishing a preceding tube in thechain but not a succeeding tube in the chain as any given tube becomesconducting, thus causing the tubes to become conducting cyclically andbecoming con-ducting serially in a given cycle, each said cycle havingone less tube in the serial operation until the last cycle, when all thetubes are left conducting.

8. A plurality of gaseous discharge triode electron tubes; electricsupply mean for said tubes suillcient to maintain conduction in anytube, the supply means for a tube including resistance; electric biassupply means for normally preventing a discharge in any of said tubes;electric impulse input means common to said tubes tending to render saidtubes conducting but normally insufficient to do so to any but a firsttube of the plurality; means interconnecting the tubes into an operativechain whereby the condition of conacoaava tinguish all the tubes comeconducting.

9. In combination, i'our gaseous discharge electron tubes; circuitssupplying operating, energy to each tube circuits for supplyingconductioncontrolling energy to each tube; connections forming the tubesinto an operative chain, the condition of conduction in a tube causingthe tube next in the chain to be primed for conduction; means connectingthe tubes so that conduction commencing in one tube will stop conductionin any preceding tube of the chain; and

input impulse circuits common to the tubes which, when impressed with animpulse, cause conduction in the first tube and any primed tube of thechain, whereby, it an operation is started with all the tubesnon-conducting, then, on the receipt of ten input impulses, all thetubes are left in a conducting condition.

10. In combination, four gaseous discharge electron tubes; circuits forsupplyingoperating energy to each tube; circuits for supplyingconduction-controlling energy to each tube connections forming the tubesinto an operative chain,

the condition of conduction in a tube causing the tube next in the chainto be primed for conduction; means connecting the tubes so thatconduction commencing in one tube will stop conduction in any precedingtube of the chain, input impulse circuits common to the tubes which,when impressed with an impulse, cause conduction in the first tube andany primed tube oi the chain, whereby, if an operation is started withall the tubes non-conducting, then, on the re-- ceipt of ten inputimpulses, all the tubes are left 4 in a conducting condition; andautomatic means to stop conduction in all the tubes when all the tubesare in a conducting condition.

' 11. In combination, four gaseous discharge electron tubes; circuitsfor supplying operating energy to each tube; circuits for supplyingconduction-controlling energy to each tube; connections forming thetubes into an operative chain, the' condition of conduction in a tubecausing the tube next in the chain to be primed for conduction; meansconnecting the tubesso that conduction commencing in one tube will stopconduction in any preceding tube of the chain; input impulse circuitscommon to the tubes which, when impressed with an impulse, causeconduction in the first tube and any primed tube of the chain,

- whereby, if an operation is started with allof the duction in a tubeprimes the next tube of the becoming conducting serially in a givencycle,

each said cycle having one less tube in the serial operation until thelast cycle, when all the tubes are left conducting; and automatic meansto extubes-non-conducting, then, on the receipt of ten input impulses,all the tubes are left in a conducting condition; and electronic meansto temporarily stop conduction in all the tubes between the receipt ofthe tenth and eleventh 1mpulses.

, 12. In combination, two vacuum electron tubes arranged in a circuitwherein one is normally conducting and one is normally non-conducting;connections between the normally non-conducting tube and the conductingtube for reversing the state of conduction oi. the pair ii thenon-conducting tube is caused to conduct; a plurality of gaseousdischarge electron tubes; and a resistance network interconnecting theplurality of gaseous discharge tubes, the normally non-conducting vacuumtube, and a source of potential so that when all the plurality ofgaseous tubes, but not any less number, are conducting, the normallynon-conducting tube is caused to conduct,

13. In combination, a plurality of gaseous discharge electron tubes; anadjustable resistance network connecting said tubes to a supply ofelecimmediately they an be-"- tric energy so that conduction in saidtubes changes the potential at a certain control point in said networkaccording in degree to the number of tubes conducting; means whenoperative for extinguishing any conducting tubes; and means connectingthe control point to the extinguishing means to cause the extinguishingmeans to operate when the control point reaches a certain potential. I

14. In combination, a plurality of electron gas discharge tubes eachhaving at least an anode, a

cathode, and a control grid; 'means supplying anode potential to saidtubes; means supplying cathode potential to said tubes including aresistance in series with each cathode, and said anodecathode potentialbeing sufficient to maintain conduction in said tubes; means to supply9. normally controlling bias potential to each tube, that supplied to afirst tube being less than the uniform controlling potential supplied tothe remainder of the tubes; means to impress positive potential impulseson the grids of all the tubes so that the first tube will normally becaused to conduct and the remaining tubes will normally only tend tobecome conducting; connections between the cathode of one tube and thegrid of another tube to form an operative chain, the act of conductionin a tube bringing the grid of the following tube to which its cathodeis connected to a potential where said following tube will becomeconducting on receipt of the next impulse, said first tube being firstin the chain; means coupling the cathodes of adjacent tubes in a chain,said couplings each having a rectifier and a capacitor in series withsaid rectifier oriented to pass a positive impulse only toward thebeginning tube of the chain; a source of electric energy and aresistance network coupled in regular pattern to the cathodes of saidtubes, said network having a control point therein whose potential 10falls to a certain low potential as all the tubes become conducting; avacuum tube arranged in a circuit so as to be normally conducting, saidcircuit including an anode resistor, said vacuum tube being coupled tosaid control point, which, when it is at said certain low potential,causes said vacuum tube to become non-conducting; and means including acapacitor and a rectifier in series coupling the anode of said vacuumtube and the cathode of the last tube of the chain whereby, when all thegaseous tubes are rendered conducting, the vacuum tube will be renderednon-conducting and cause all the gas tubes to be reset to anon-conducting condition, which in turn causes the vacuum tube to againbecome conducting.

15. In combination, a source of direct current; a plurality of electricdischarge devices oi! the arc-like type connected in parallel circuitsacross said source; connection forming the devices into an operativechain, the condition of an arc in a device causing the device next inthe chain to be primed for arcing; means connecting the devices so thatarcing commencing in one device will stop arcing in any preceding deviceof the chain; and an input impulse circuit coupled commonly to thedevices, which circuit, when impressed with an impulse, causes an arc inthe first device of the chain and also causes an arc in. any primeddevice of the chain, whereby, if an operation is started with alldevices in a non-arcing condition, then, on the receipt of a number 01impulses equal to where N equals the number of devices, all the

